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Associations between the prevalence of Mollicutes and Mycoplasma bovis and health and performance in stocker calves
Author(s) -
Hanzlicek G. A.,
White B. J.,
Renter D. G.,
Anderson D. E.,
Larson R. L.
Publication year - 2011
Publication title -
veterinary record
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.261
H-Index - 99
eISSN - 2042-7670
pISSN - 0042-4900
DOI - 10.1136/vr.c5965
Subject(s) - seroconversion , seroprevalence , mycoplasma , weight gain , medicine , mollicutes , serostatus , incidence (geometry) , bovine respiratory disease , biology , veterinary medicine , serology , zoology , antibody , immunology , body weight , microbiology and biotechnology , virus , viral load , physics , optics
A longitudinal cross‐sectional time‐series study was carried out to determine the prevalence of nasal mycoplasma carriage, serostatus and seroconversion, and to evaluate the associations between these parameters and health and performance in weaned beef calves during a 42‐day feeding period. Nasal swabs and serum were collected on days 0 (arrival), 10, 42 and at the first incidence of bovine respiratory disease complex. The samples were evaluated for Mollicutes (by culture), Mycoplasma bovis (by PCR) and serum antibody to M bovis . On day 0, 90.4 per cent of the calves were Mollicutes nasal culture‐positive. The seroprevalence of M bovis was 26.6 per cent on day 0 and 98.2 per cent by day 42 (P<0.05). Seroconversion to M bovis between days 0 and 42 was significantly associated (P=0.04) with lower weight gain. Weight gain was greater in calves that were PCR‐negative for M bovis on day 10 (P=0.01) . The percentage of calves seropositive to M bovis increased throughout the study, indicating exposure and an immunological response to the organism. Although associations with health outcomes were not identified, seroconversion to M bovis was associated with a decreased rate of weight gain during the study period.